大象传媒

In Costa Rica, the first recorded example of a crocodile that made herself pregnant - know as parthenogenesis -has been verified in one of the country's zoos.

The egg was laid by the female reptile despite spending her entire adult life in her own enclosure without exposure to male crocodiles. The phenomenon of a so-called "virgin birth" has been found in species of birds, fish and other reptiles, but never confirmed before in crocodiles.

But they may not be that unusual according to the person who verified this, Professor Warren Booth of the Urban Evolutionary Entomology Lab at Virginia Tech University.

Speaking to Newsday, Prof Booth said: "All of the eggs failed to hatch. But in one they found a fully-formed but still-born female crocodile. We DNA-sequenced the genome of the crocodile and of the offspring and we found it lacked any genetic material that could have come from a male."

"What's really exciting is crocodiles belong to [the same] group of organisms... that includes birds. Between the crocodiles and the birds you get the pterosaurs and the dinosaurs. So the fact that crocodiles and birds use the exact same complex parthenogenetic method suggests very strongly that pterosaurs and dinosaurs also had the ability to produce parthenogenetically."

(Pic: A baby crocodile emerges from its shell; Credit: Joe Wasilewski)

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